The data of one of the planets is deleted, why's that?

Why was Oddy meant to be put into cryostasis? Illness? But I couldn't find clues about illness entire game. Shuttle isn't big enough for Oddy? In the happy ending captain says "We'll all go to do it together. " I think it implies the shuttle is big enough for rest of the crews.

And...The warp engine is designed to fly to black holes, well...how do they get back to Earth then?